South Africans hate it when foreigners write about what might happen when he passes away. So let me offer my apologies and – with all due deference – suggest that Mandela’s departure will have an even deeper impact than some anticipate.

There will, of course, be heartfelt grief in South Africa and worldwide. But something more profound will also change. Even at the age of 94, after a decade or so of retirement, Mandela is woven into the fabric of his country’s political settlement. He is the silent guarantor of a democratic and free South Africa. In that sense, he remains the informal head of state.

South Africans see him a living reminder of the triumph of 1994, when their country achieved the seemingly impossible by carrying out a peaceful transition to majority rule. As such, Mandela is the symbol of the “Rainbow Nation”, of the new South Africa summoned into being by the idealism of the democratic constitution that he helped to create.

For as long as he is around, South Africans believe their present leaders will be slightly more likely to stick to the principles of the nation’s rebirth 18 years ago. In a way that foreigners can’t really grasp, Mandela still underwrites that settlement with all its promise and idealism.

For as long as he lives, South Africans breathe a little easier and believe in their country a little more. When the day after Mandela dawns, that belief will be shaken, not dramatically or immediately, but slowly and perhaps imperceptibly. South Africa will, quite simply, be a different country.